- Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test with a sensitivity of at least 50 mIU/mL within 10 - 14 days prior to and again within 24 hours of prescribing lenalidomide and must either commit to continued abstinence or TWO acceptable methods of birth control. FCBP must also agree to ongoing pregnancy testing. Males must agree to use a latex condom.